Optimization of hybrid iterative reconstruction level and evaluation of image quality and radiation dose for pediatric cardiac computed tomography angiography

• Published in: Pediatric radiology Vol. 47; no. 1; pp. 31 - 38
• Main Authors: Yang, Lin, Zhuang, Jian, Huang, Meiping, Liang, Changhong, Liu, Hui
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.01.2017; Springer Nature B.V
• Subjects: Computed Tomography Angiography - standards; Contrast Media; Coronary Angiography - standards; Female; Heart Defects, Congenital - diagnostic imaging; Humans; Imaging; Infant; Infant, Newborn; Male; Medicine; Medicine & Public Health; Neuroradiology; Nuclear Medicine; Oncology; Original Article; Pediatrics; Prospective Studies; Radiation Dosage; Radiographic Image Interpretation, Computer-Assisted - standards; Radiology; Ultrasound; Hybrid iterative reconstruction; Radiation dose; Congenital heart disease; Children; Angiography; Computed tomography
• ISSN: 0301-0449; 1432-1998
• DOI: 10.1007/s00247-016-3698-4

Background Hybrid iterative reconstruction can reduce image noise and produce better image quality compared with filtered back-projection (FBP), but few reports describe optimization of the iteration level. Objective We optimized the iteration level of iDose 4 and evaluated image quality for pediatric cardiac CT angiography. Materials and methods Children ( n  = 160) with congenital heart disease were enrolled and divided into full-dose ( n  = 84) and half-dose ( n  = 76) groups. Four series were reconstructed using FBP, and iDose 4 levels 2, 4 and 6; we evaluated subjective quality of the series using a 5-grade scale and compared the series using a Kruskal-Wallis H test. For FBP and iDose 4 -optimal images, we compared contrast-to-noise ratios (CNR) and size-specific dose estimates (SSDE) using a Student’s t -test. We also compared diagnostic-accuracy of each group using a Kruskal-Wallis H test. Results Mean scores for iDose 4 level 4 were the best in both dose groups (all P  < 0.05). CNR was improved in both groups with iDose 4 level 4 as compared with FBP. Mean decrease in SSDE was 53% in the half-dose group. Diagnostic accuracy for the four datasets were in the range 92.6–96.2% (no statistical difference). Conclusion iDose 4 level 4 was optimal for both the full- and half-dose groups. Protocols with iDose 4 level 4 allowed 53% reduction in SSDE without significantly affecting image quality and diagnostic accuracy.